Apparatus for the collection and transmission of electromagnetic radiation

ABSTRACT

A collector for propagating incident radiation is disclosed. The collector may comprise a light directing component coupled to a buffer component, a first propagation component coupled to the buffer component and configured to transmit the incident radiation into a collector region through one of a plurality of windows, and an optical transport assembly coupled to an end of the collector region and having a second propagation component. Each light directing component may be configured to redirect the incident radiation from a first direction to a second direction, and the collector region may include a plurality of regions exhibiting a refractive index value that gradually transitions from about 1.5 to about 2.0. The second propagation component may be further configured to retain the incident radiation.

REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of U.S. patent applicationSer. No. 12/574,282, filed Oct. 6, 2009, which is a continuation of U.S.patent application Ser. No. 12/042,214, filed Mar. 4, 2008, now U.S.Pat. No. 7,606,456, which is a continuation of U.S. patent applicationSer. No. 11/623,208, filed Jan. 15, 2007, now U.S. Pat. No. 7,369,735,which is a continuation-in-part of U.S. patent application Ser. No.11/215,789, filed Aug. 30, 2005, now U.S. Pat. No. 7,164,839, which is adivisional of U.S. patent application Ser. No. 10/369,052, filed Feb.18, 2003, now U.S. Pat. No. 6,957,650, the disclosures of which arehereby expressly incorporated in their entirety by this reference. Thispatent application also claims the benefit of U.S. ProvisionalApplication No. 60/357,705, filed on Feb. 15, 2002, the disclosure ofwhich is hereby expressly incorporated by reference.

BACKGROUND AND SUMMARY OF THE INVENTION

The present invention relates to collectors configured to collectelectromagnetic radiation and in particular, collectors configured tocollect solar radiation and further relates to optical connectors forcoupling radiation from a first optical component to a second opticalcomponent.

Solar energy collectors have used holographic elements to alter thedirection of incident sunlight. Such example solar collectors includeU.S. Pat. No. 4,863,224; U.S. Pat. No. 5,877,874, and U.S. Pat. No.6,274,860. However, each of these systems discuss the need to alter theholographic element at various spatial regions in order to avoidunwanted decoupling of solar energy from the solar collector. Suchrequirements result in complex systems which are not practical.

In one exemplary embodiment of the present invention, a radiationcollector configured to collect incident radiation is provided. Theradiation collector includes a radiation directing component configuredto redirect the incident radiation, a buffer component configured toreceive the radiation redirected by the radiation directing component,and a propagation component configured to receive the radiation from thebuffer component and to propagate the radiation by at least totalinternal reflection. Other embodiments of the present invention furtherinclude connectors for coupling radiation from a first optical componentto a second optical component.

In another exemplary embodiment, a collector for collecting radiationincident on the collector from at least a first direction comprises apropagation component configured to transmit radiation and having afirst end and at least a first refractive index; a buffer componentcoupled to the propagation component and configured to transmitradiation and having at least a second refractive index, the secondrefractive index being less than the first refractive index of thepropagation component; and a radiation directing component coupled tothe buffer component and configured to redirect the incident radiationfrom the at least first direction along at least a second directiondifferent than the first direction within the buffer component, suchthat the radiation enters the propagation component and is propagatedwithin the propagation component toward a first end of the propagationcomponent by at least total internal reflection. In one example, theradiation is solar radiation and the buffer component is positionedrelative to the propagation component and the radiation directingcomponent, such that the radiation propagating in the propagationcomponent is prevented from interacting with the radiation directingcomponent.

In yet another exemplary embodiment, a collector for collectingradiation incident on the collector from at least a first directioncomprises a radiation directing component configured to redirect theincident radiation; a buffer component coupled to the radiationdirecting component and configured to receive the radiation redirectedby the radiation directing component; and a propagation componentcoupled to the buffer component and configured to receive the radiationfrom the buffer component and to propagate the radiation generally in afirst direction toward a first end of the propagation component by atleast total internal reflection, the radiation directing component beingpositioned such that the radiation incident on the collector which isreceived into the propagation component is incident from a directiongenerally not parallel with the first direction of the propagationcomponent.

In a further exemplary embodiment, a solar collector configured tocollect incident solar radiation and to be affixed to a surface of abuilding comprises an optical component having a top surface and a firstend, the optical component configured to receive the incident solarradiation through the top surface and to collect the incident solarradiation at the first end of the optical component; and an attachmentcomponent coupled to the optical component, the attachment componentconfigured to receive at least one fastening components to secure theattachment component to the surface of the building.

In one exemplary method, a method of collecting incident radiationcomprises the steps of receiving the incident radiation from at least afirst direction; redirecting the incident radiation with a radiationdirecting component into a propagation component; retaining theradiation in the propagation component such that the radiation ispropagated generally toward a first end of the propagation component;and optically separating the radiation component from the propagationcomponent such that the radiation propagating with the propagationcomponent is prevented from interacting with the radiation directingcomponent.

In another exemplary method, a method of coupling optical radiation fromat least a first source of optical radiation into a first opticaltransport component including a first propagation component and a firstbuffer component, the first buffer component radially overlaying thefirst propagation component and the first optical transport componentconfigured to propagate optical radiation in generally a first directiontoward a first end of the first optical transport component or ingenerally a second direction toward a second end of the first opticaltransport component comprises the steps of positioning the at leastfirst source of optical radiation adjacent an exterior radial surface ofthe first buffer component; and directing at least a portion of theradiation emanating from the source of optical radiation into the firstbuffer component of the first optical transport component such that theradiation is coupled into the first propagation component and ispropagated within the first propagation component toward at least one ofthe first end or the second end of the first propagation component dueat least to total internal reflection between the first propagationcomponent and the second component.

In yet a further exemplary embodiment, an optical connector fortransferring radiation comprises a first optical transport componentincluding a first propagation component and a first buffer component,the first buffer component radially overlaying the first propagationcomponent, the first optical transport component configured to propagateoptical radiation in generally a first direction toward a first end ofthe first optical transport component; a second optical transportcomponent including a second propagation component and a second buffercomponent, the second buffer component radially overlaying the secondpropagation component, the second optical transport component configuredto propagate optical radiation in generally a second direction toward asecond end of the second optical transport component, the second opticaltransport component being positioned such that the second direction isnot parallel to the first direction; and a radiation directing componentlocated proximate to the first end of the first optical transportcomponent and proximate to an exterior surface of the buffer componentof the second optical transport component, the radiation directingcomponent configured to redirect the optical radiation propagatinggenerally in the first direction through the exterior surface of thesecond optical transport into the second propagation component such thatthe optical radiation is propagated within second optical transportcomponent generally along the second direction of the second opticaltransport component.

In still another exemplary embodiment, a method of propagating collectedincident radiation to a remote location is provided. The methodcomprises receiving the incident radiation from at least a firstdirection; redirecting the incident radiation with a light directingcomponent into a first propagation component having a plurality ofwindows contained therein, the light directing component being coupledto a buffer component configured to optically separate the lightdirecting component and the first propagation component and to retainthe incident radiation in the first propagation component; propagatingthe incident radiation into a collector region through one of theplurality of windows within the first propagation component; advancingthe incident radiation within the collector region generally towards anend of the collector region, the radiation encountering a plurality ofregions exhibiting a refractive index value that gradually transitionsfrom about 1.5 to about 2.0 while advancing towards the end of thecollector region; and directing the incident radiation into an opticaltransport assembly having a second propagation component, the secondpropagation component being configured to retain the incident radiationtherein for being propagated to the remote location.

In another exemplary embodiment, a collector for propagating incidentradiation to a remote location is provided. The collector comprises alight directing component coupled to a buffer component, each lightdirecting component being configured to redirect the incident radiationfrom a first direction to a second direction; a first propagationcomponent coupled to the buffer component and configured to transmit theincident radiation into a collector region through one of a plurality ofwindows, the collector region including a plurality of regionsexhibiting a refractive index value that gradually transitions fromabout 1.5 to about 2.0; and an optical transport assembly coupled to anend of the collector region and having a second propagation component,the second propagation component being configured to retain the incidentradiation

Additional features of the present invention will become apparent tothose skilled in the art upon consideration of the following detaileddescription of the preferred embodiment exemplifying the best mode ofcarrying out the invention as presently perceived.

BRIEF DESCRIPTION OF THE DRAWINGS

The detailed description of exemplary embodiments particularly refers tothe accompanying figures in which:

FIG. 1 is an exploded, perspective view of a first embodiment of a solarcollector including a radiation directing component, a buffer component,and a propagation component;

FIG. 2 is a cross-section view of the solar collector of FIG. 1corresponding to the solar collector in an assembled configuration;

FIG. 3 is an exploded, perspective view of a second embodiment of asolar collector including a radiation directing component, a firstbuffer component, a propagation component, and a second buffercomponent;

FIG. 4 is a cross-section view of the solar collector of FIG. 3corresponding to the solar collector in an assembled configuration;

FIG. 5 is a perspective view of a third embodiment of a solar collectorincluding a radiation directing component, a propagation component, anda buffer component, the buffer component surrounding the propagationcomponent except for at least a first surface of the propagationcomponent;

FIG. 6A is a diagrammatic representation of a non-tracking embodiment ofthe present invention including a solar collector coupled to an energyconverting component;

FIG. 6B is a diagrammatic representation of a tracking embodiment of thepresent invention including a solar collector coupled to a frame and toan energy converting component, the frame and the solar collector beingmoveable and positionable by a tracking component;

FIG. 6C is a diagrammatic representation of a tracking embodiment of thepresent invention including a solar collector, coupled to an energyconverting component, the solar collector and the energy convertingcomponent being coupled to a frame, the frame, solar collector, andenergy converting component being moveable and positionable by atracking component;

FIG. 7A is top view of the solar collector of FIG. 5 coupled to a secondsolar collector and an optical transport component through an adaptorcomponent, the adapter component tapering from a generally quadrilateralcross-section to a generally circular cross-section;

FIG. 7B is a cross-section view of the solar collector and second solarcollector of FIG. 7A;

FIG. 7C is a perspective view of the solar collector of FIG. 7A showingthe adapter and the optical transport component in an explodedconfiguration;

FIG. 7D is a side view of the solar collector of FIG. 7A and a secondsolar collector having a generally circular cross-section;

FIG. 7E is a side view of a first and a second solar collector coupledto an intermediate solar collector, the intermediate solar collectorhaving a first radiation directing component for coupling the firstsolar collector and a second radiation directing component for couplingthe second solar collector;

FIG. 8 is a schematic, side, elevational representation of a buildinghaving a plurality of solar collectors affixed to a roof of thebuilding;

FIG. 9A is a perspective view of a first embodiment of a solar sheeting,the solar sheeting comprising a solar collector coupled to an attachmentcomponent;

FIG. 9B is an exploded, perspective view of a second embodiment of asolar sheeting, the solar sheeting comprising a solar collector and anattachment component;

FIG. 10 is an exploded, perspective view of a solar collector includinga plurality of radiation directing components positioned within a firstbuffer component, a propagation component, and a second buffercomponent;

FIG. 11 is a cross-section view of the solar collector of FIG. 10corresponding to the solar collector in an assembled configuration;

FIG. 12A is a perspective view of an exemplary optical connector in anassembled configuration;

FIG. 12B is an exploded, perspective view of the optical connector ofFIG. 12A;

FIG. 13 is a diagrammatic view of an optical network;

FIG. 14 is a cross-section view of an optical transport component forconnecting two solar collectors;

FIGS. 15 a and 15 b are exploded perspective views of additionalexemplary photocollector embodiments in accordance with the presentteachings;

FIG. 15 c is a perspective view of the photocollector of FIG. 15 ashowing the optical transport component in an exploded configuration;

FIG. 16 is a cross-section view of the photocollector of FIG. 15 a shownin an assembled configuration; and

FIG. 17 shows a cross-section view of the buffer component region of thephotocollector from FIG. 15 a showing the interaction of light rays withthe concavity design of the louvers.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

While the invention is susceptible to various modifications andalternative forms, exemplary embodiments thereof have been shown by wayof example in the drawings and will herein be described in detail. Itshould be understood, however, that there is no intent to limit theinvention to the particular forms disclosed, but on the contrary, theintention is to cover all modifications, equivalents, and alternativesfalling within the spirit and scope of the invention as defined by theappended claims.

Referring to FIG. 1, a first embodiment of a radiation or solarcollector 100 is shown. Solar collector 100 includes a radiation orlight directing component 110, a buffering component 120, and apropagation component 130. As described in detail below, radiation orlight directing component 110 is configured to redirect at least aportion of the incident solar radiation 140 on solar collector 100 intopropagation component 130, propagation component 130 is configured tocollect the portion of solar radiation redirected by light directingcomponent 110, and buffer component 120 is configured to opticallyseparate light directing component 110 and propagation component 130 andto retain the collected radiation in propagation component 130.

Referring to FIG. 2, a schematic cross-section of an assembled solarcollector 100 is shown, along with the interaction of incident solarrays 140 a, and 140 b with solar collector 100. Rays 140 a and 140 b arerepresentative of the incident solar radiation. Although light rays 140a and 140 b are generally incident on solar collector 100 from adirection 139, it is understood that the incident solar radiation may befrom one or more additional directions. In the illustrated embodiment,light directing component 110 and buffer component 120, as well asbuffer component 120 and propagation component 130 are coupled togetherwith at least one of a variety of optical adhesives known in the art forcoupling optic media. Exemplary optical adhesives include opticalepoxies and optical cements. Exemplary optical epoxies include epoxiesavailable from MasterBond, Inc. located at 154 Hobart Street inHackensack, N.J. 07601 and exemplary cements from Summers Opticallocated at 321 Morris Road, PO Box 162 in Fort Washington, Pa. 19034. Itis preferred to use optical adhesives which are index matching adhesiveswhich have an index of refraction in close approximation to at least oneof the components being coupled together. It is preferred to use opticaladhesives which are configured for use in applications that are exposedto long durations of solar radiation.

Radiation or light directing component 110 is configured to redirectsolar radiation incident from at least a first direction 139, asrepresented by rays 140 a and 140 b along at least a second direction143 into buffer component 120, as represented by rays 142 a and 142 b.Rays 142 a and 142 b propagate through buffer component 120 and areincident on propagation component 130 at an angle, θ_(142a) and θ_(142b)respectively, with the normal of an interface 124 between buffercomponent 120 and propagation component 130 such that rays 142 a and 142b are refracted into propagation component 130 as light rays 144 a and144 b. Light rays 144 a and 144 b propagate in propagation component 130generally in a direction 141 toward a first end 132 of solar collector100. The direction of light rays 142 a and 142 b, as well as, theproperties of buffer component 120 and propagation component 130 arechosen such that light rays 144 a and 144 b are retained withinpropagation component 130 at subsequent interactions with interface 124between buffer component 120 and propagation component 130 and a lowerinterface 126 between propagation component 130 and the outside medium,such as air. In one example, light rays 144 a and 144 b are retainedwithin propagation component 130 by substantially total internalreflection. In another example, interface 126 includes a reflectioncoating (not shown), such as a mirrored surface, and light rays 144 aand 144 b are retained within propagation component 130 due to beingreflected by the reflection coating on interface 126. In anotherexample, light rays 144 a and 144 b are retained in propagationcomponent 130 due to at least one of total internal reflection andreflection from a reflection coating. In yet a further example, at leastone edge surface 121 and 131, of either or both buffer component 120 andpropagation component 130 includes a reflection coating to retain solarradiation in buffer component 120 and propagation component 130.However, it should be noted that solar radiation may also be retained inpropagation component 130 at surface 131 and buffer component 120 atsurface 121 due to total internal reflection.

Light directing component 10, in a first embodiment, includes aholographic element, such as a film hologram or a volume hologram. In asecond embodiment, light directing component 110 includes a diffractiongrating or ruling. The design of holographic elements and/or diffractiongratings or rulings to redirect light incident from at least a firstdirection 139, such as the direction of light rays 140 a and 140 b inFIG. 2, along at least a second direction 143, such as the direction oflight rays 142 a and 142 b is known.

Holographic elements are generally configured to redirect radiation thathas a wavelength band approximate in value to the wavelength used torecord the holographic element. Since solar radiation includes radiationat many different wavelengths, including the entire visible spectrum, itis preferred to use holographic elements which are configured toredirect incident radiation from multiple wavelength bands along atleast the second direction 143. In one example, light directingcomponent 110 contains multiple layered holographic elements, eachholographic element being configured to redirect radiation approximateto a different wavelength band. In another example, multiple wavelengthsare used in the recording of light directing component 110 in a singlefilm. Light directing component 110 includes a plurality of fringepatterns each created by a recording beam pair having a differentrecording wavelength such that the resultant light directing componentis capable of redirecting radiation from several different wavelengths.

Further, holographic elements are generally configured to redirectradiation that is incident from one of the directions used to record theholographic element, the directions of the recording beam pairs. Sincesolar radiation is incident on solar collector 100 from directions inaddition to first direction 139, it is preferred to use holographicelements which are configured to redirect radiation from multipleincident directions including direction 139 along at least seconddirection 143 or other directions that allow the radiation to bepropagated within the corresponding propagation component 130 by totalinternal reflection and/or reflection from a reflection coating. In oneexample, light directing component 110 contains multiple layeredholographic elements, each holographic element being configured toredirect radiation from a different given incident direction such thatthe radiation is propagated in the propagation component by totalinternal reflection and/or reflection from a reflection coating. Inanother example, light directing component 110 includes a plurality offringe patterns in a single film produced by recording a plurality ofrecording beams pairs each of which interfere to produce a holographicstructure which will accept light from a range of input angles andoutput the light into a different range of angles chosen such that theoutput light is coupled into the propagation component.

Diffraction gratings and ruling can also be configured to redirectradiation of several wavelength bands and radiation from severalincident directions into the propagation component such that theradiation is propagated in the propagation component by total internalreflection and/or reflection from a reflection coating. For example, thespacing of the grating can be varied either along a lateral extent ofthe grating or by placing gratings having different spacing adjacenteach other.

In the illustrated embodiment, buffer component 120 is a refractivemedia having at least a first index of refraction, denoted as n₁₂₀,propagation component 130 is a refractive media having at least a secondindex of refraction, denoted as n₁₃₀, and the index of refraction of theoutside media at the lower interface 126 is denoted as n_(out). Bothbuffer component 120 and propagation component 130 are manufactured frommaterials having a high degree of optical transmission and lowadsorption properties. Further, the index of refraction of propagationcomponent 130, n₁₃₀, has a greater value than the index of refraction ofbuffer component 120, n₁₂₀, and the index of refraction of the outsidemedium, n_(out), thereby permitting total internal reflection of thesolar radiation in propagation component 130.

In one example propagation component 130 includes a refractive mediasuch as a suitable plastic or glass and buffer component 120 includes arefractive media having a low index of refraction than propagationcomponent 130, the buffer refractive media being a suitable plastic,glass, liquid or air. In another example the propagation component orthe propagation component and the buffer component have a graded-indexprofile.

Referring to FIG. 2, as already noted, light rays 140 a and 140 b areincident from at least a first direction 139 and are redirected by lightdirecting component 110 along at least second direction 143 as lightrays 142 a and 142 b. Further, light rays 142 a and 142 b are refractedinto propagation component 130 as light rays 144 a and 144 b andsubsequent rays, such as 146 a and 146 b and 148 a and 148 b. Thepropagation of light ray 144 b is governed by the same principles aslight ray 144 a. As such, it is understood that the following discussionof the propagation of light ray 144 a is representative of light rays144 a and 144 b, as well as additional light rays.

The direction of light ray 144 a in propagation component 130 relativeto the normal of interface 124 at the point of entry of light ray 144 ais governed by the equation:

n ₁₂₀ Sin(θ_(142a))=n ₁₃₀ Sin(θ_(144a1))  (1)

Light ray 144 a travels through propagation component 130 and isincident on interface 126 at an angle θ_(144a2) with respect to thenormal of interface 126 at the point of incidence of light ray 144 a. Atinterface 126 light ray 144 a will be either refracted into the outsidemedia or be reflected within propagation component 130 as light ray 146a. The direction of light ray 146 a is governed by the equation:

n ₁₃₀ Sin(θ_(144a2))=n _(out) Sin(θ_(out))  (2)

The angle θ_(out) corresponds to the angle light ray 146 a would makewith the normal of interface 126 at the point of incidence of light ray144 a if light ray 146 a is refracted into the outside media, n_(out).

Light ray 146 a may be retained within propagation component 130 byeither reflection from a reflection coating (not shown) at interface 126or by total internal reflection at interface 126. In order for light ray146 a to be totally internally reflected within propagation component130, 74 _(out) must be equal to or greater than 90°, such that θ_(144a1)is less than or equal to 90°. The value of θ_(out) may be greater thanor equal to 90° when n_(out) is less than n₁₃₀. As such, in order forlight ray 146 a to be totally internally reflected the followingrestriction should be satisfied:

$\begin{matrix}{\theta_{144a\; 2} \geq {{{Sin}^{- 1}( \frac{n_{out}}{n_{130}} )}\mspace{14mu} {where}\mspace{14mu} n_{out}} < n_{130}} & (3)\end{matrix}$

Therefore, as long as θ_(144a2) is greater than or equal to the quantitySin⁻¹(n_(out)/n₁₃₀), light ray 144 a is totally internally reflectedwithin propagation component 130 as light ray 146 a. However, ifθ_(144a2) is less than the quantity Sin⁻¹ (n_(out)/n₁₃₀), light ray 144a may still be reflected into propagation component 130 due to areflection coating at interface 126. As seen from equation (3), thedifference in value of n_(out) and n₁₃₀ controls the range of acceptableangles, θ_(144a2), for total internal reflection. Table 1 shows thedifference in acceptable angles, θ_(144a2), for various exemplarycombinations of n_(out) and n₁₃₀.

TABLE 1 Comparison of Acceptable angles for total internal reflectionn_(out) = 1.0 (air) n₁₃₀ = 1.49 (acrylic) θ_(144a2) ≧ 42.2° n_(out) =1.0 (air) n₁₃₀ = 1.586 (polycarbonate) θ_(144a2) ≧ 39.1° n_(out) = 1.49(acrylic) n₁₃₀ = 1.586 (polycarbonate) θ_(144a2) ≧ 70.0° n_(out) = 1.49(acrylic) n₁₃₀ = 2.02 (glass N- θ_(144a2) ≧ 47.5° LASF35)* *N-LASF35glass along with additional suitable glass is available from Schott-Glaslocated at Business Segment Display, Hattenbergstr. 10, 55122 Mainz,Germany.

As seen in Table 1, the larger the difference in n_(out) and n₁₃₀ thegreater range of acceptable angles, θ_(144a2), that satisfy thecondition of equation (3).

In the same manner light ray 146 a is totally internally reflected atinterface 124 as light ray 148 a when θ_(146a2) is greater than or equalto the quantity Sin⁻¹ (n₁₂₀/n₁₃₀) as expressed in equation (4).

$\begin{matrix}{\theta_{146\; a\; 2} \geq {{{Sin}^{- 1}( \frac{n_{120}}{n_{130}} )}\mspace{14mu} {where}\mspace{14mu} n_{120}} < n_{130}} & (4)\end{matrix}$

As such, light ray 144 a remains in propagation component 130 andpropagates toward first end 132 of propagation component 130 as long asthe relations in equations (3) and (4) are satisfied. It is understoodthat subsequent rays such as light ray 148 a are retained in propagationcomponent 130 as light ray 150 a by reflection from a reflection coatingor by total internal reflection.

It should be noted that although solar collector 100 is shown in FIG. 2as a planar device, the invention is not limited to planar solarcollectors nor are equations (3) and (4). On the contrary, in oneembodiment, solar collector 100 is made of flexible material such thatlight directing component 110, buffer component 120 and propagationcomponent 130 are not rigid, but able to bend. Further, propagationcomponent 130 may be tapered such that an overall height or width ofpropagation component 130 is reduced or enlarged. However, in order forthe solar collector to capture solar radiation in propagation component130 and have that solar radiation propagate towards first end 132, thedegree of bend of propagation component 130 and buffer component 120 orthe degree of tapering of propagation component 130 is restricted by theangular requirement for total internal reflection given above inequations (3) and (4).

Further, in one variation, solar collector 100 includes a protectivelayer of material (not shown) that protects light directing component110 from direct exposure to the elements and other sources of possibledamage.

In one embodiment of solar collector 100, light directing component 110is configured to redirect incident solar radiation by reflection insteadof transmission. As such, incident solar radiation from a direction 145,shown in FIG. 2 passes through propagation component 130 and buffercomponent 120 and is incident on light directing component 110. Lightdirecting component 110 is configured to redirect the incident solarradiation back through buffer component 120 and wherein the solarradiation is retained in propagation component 130 due to at least totalinternal reflection. In one example light directing component 110includes a holographic element configured to reflect the incident solarradiation.

Referring to FIG. 3, a solar collector 200 is shown. Solar collector 200is generally identical to solar collector 100 and comprises a lightdirecting component 210, a first buffer component 220, a propagationcomponent 230, and a second buffer component 260 which is coupled to thelower side of propagation component 230. Light directing component 210,in one example, includes a holographic element. Light directingcomponent 210, in another example, includes a diffraction grating orruling. Propagation component 230, in one example, is made of arefractive media such as a suitable plastic or glass or liquid. Buffercomponents 220 and 260, in one example, are comprised of a refractivemedia having a lower index of refraction than propagation component 230such as a plastic material, a glass material, a liquid, or air.

Light directing component 210, first buffer component 220, propagationcomponent 230 and second buffer component 260 are coupled together witha suitable optical adhesive. Second buffer component 260 providesprotection to propagation component 230 to minimize potential damage topropagation component 230. Further, as indicated in FIG. 4, secondbuffer component 260 has an index of refraction, n₂₆₀, which is equal tothe index of refraction of first buffer component 220, n₂₂₀. As such,the range of acceptable angles, θ_(244a2) and θ_(246a2) for totalinternal reflection, are the same for both interface 224 and interface226. In one embodiment, interface 226 between propagation component 230and second buffer component 260 includes a reflection coating to reflectrays not within the range of acceptable angles. In another embodiment,surfaces 221, 231, and 261 of first buffer component 220, propagationcomponent 230, and second buffer component 260 include a reflectioncoating.

Referring to FIG. 4, light rays 240 a and 240 b are redirected by lightdirecting component 210 from at least a first direction 239 along atleast a second direction 243 as light rays 242 a and 242 b. Further,light rays 242 a and 242 b are refracted into propagation component 230as light rays 244 a and 244 b and subsequent rays, such as 246 a and 246b and 248 a and 248 b. The propagation of light ray 244 b is governed bythe same principles as light ray 244 a. As such, it is understood thatthe following discussion of the propagation of light ray 244 a isrepresentative of light rays 244 a and 244 b, as well as additionallight rays.

The direction of light ray 244 a in propagation component 230 relativeto the normal of interface 224 at the point of entry of light ray 244 ais governed by the equation:

n ₂₂₀ Sin(θ_(242a))=n ₂₃₀ Sin(θ_(244a1))  (5)

Light ray 244 a travels through propagation component 230 and isincident on interface 226 at an angle θ_(244a2) with respect to thenormal of interface 226 at the point of incidence of light ray 244 a. Atinterface 226 light ray 244 a will be either refracted into secondbuffer component 260 or be reflected within propagation component 230 aslight ray 246 a. The direction of light ray 246 a is governed by theequation:

n ₂₃₀ Sin(θ_(244a2))=n ₂₆₀ Sin(θ₂₆₀)  (6)

The angle θ₂₆₀ corresponds to the angle light ray 246 a would make withthe normal of interface 226 at the point of incidence of light ray 244 aif light ray 244 a is refracted into second buffer component 260. Inorder for light ray 246 a to be totally internally reflected withinpropagation component 230, θ₂₆₀ must be equal to or greater than 90°,such that θ_(246a1) is less than or equal to 90°. The value of θ₂₆₀ maybe greater than or equal to 90° when n₂₆₀ is less than n₂₃₀. As such, inorder for light ray 246 a to be totally internally reflected thefollowing restriction should be satisfied:

$\begin{matrix}{\theta_{244\; a\; 2} \geq {{{Sin}^{- 1}( \frac{n_{260}}{n_{230}} )}\mspace{14mu} {where}\mspace{14mu} n_{260}} < n_{230}} & (7)\end{matrix}$

Therefore, as long as θ_(244a2) is greater than or equal to the quantitySin⁻¹(n₂₆₀/n₂₃₀), light ray 244 a is totally internally reflected withinpropagation component 230 as light ray 246 a. As seen from equation (7),the difference in value of n₂₃₀ and n₂₆₀ controls the range ofacceptable angles, θ_(244a2), for total internal reflection. The largerthe difference in n₂₆₀ and n₂₃₀ the greater range of acceptable angles,θ_(244a2), that satisfy the condition of equation (7).

In the same manner light ray 246 a is totally internally reflected atinterface 224 as light ray 248 a when θ_(246a2) is greater than or equalto the quantity Sin⁻¹(n₂₂₀/n₂₃₀) as expressed in equation (8).

$\begin{matrix}{\theta_{246a\; 2} \geq {{{Sin}^{- 1}( \frac{n_{220}}{n_{230}} )}\mspace{14mu} {where}\mspace{14mu} n_{220}} < n_{230}} & (8)\end{matrix}$

As such, light ray 244 a and subsequent light rays 246 a, 248 a, and 250a remain in propagation component 230 and propagates toward first end232 of propagation component 230 generally in direction 241 as long asthe relations in equations (7) and (8) are satisfied. When n₂₆₀=n₂₂₀,equations (7) and (8) provide identical ranges of acceptable angles.

Referring to FIG. 5, a solar collector 300 is shown. Solar collector 300comprises a light directing component 310, a buffer component 320, and apropagation component 330. Solar collector 300 is generally identical tosolar collector 100 and solar collector 200. Light directing component310, in one example, includes at least one holographic element. Lightdirecting component 310, in another example, includes at least onediffraction grating or ruling. Propagation component 330, in oneexample, includes a refractive media such as a suitable plastic or glassor liquid. Buffer component 320, in one example, includes a refractivemedia having a lower index of refraction than propagation component 330such as a plastic material, a glass material, a liquid, or air.

The buffer component 320 of solar collector 300 includes a top portion322, a bottom portion 324, a first side portion 326, a second sideportion 328, and a rear portion 329 which provide a constant interfacearound the entire propagation component 330 except for a portion 332located at a first end 302 of solar collector 300. Light directingcomponent 310 is configured to redirect incident solar radiation from atleast a first direction 339, denoted by rays 340, such that the solarradiation is coupled into propagation component 330 and generallypropagates along direction 342 within propagation component 330 due toat least total internal reflection at the interface between propagationcomponent 330 and buffer component 320. The light propagating in thegeneral direction 342 exits solar collector 300 from portion 332 ofpropagation component 330 at first end 302 of solar collector 300.

In one embodiment, buffer component 320 provides a constant interfacearound the entire propagation component 330 such that propagationcomponent 330 is sealed from the exterior of collector 300 and radiationdirecting component 310 is configured to redirect radiation emanatingfrom an optical source, such as the sun, a laser, a laser diode, or aphosphorescence or fluorescence material. The radiation from theradiation source is coupled into propagation component 330 by radiationdirecting component 310 and is retained within propagation component 330by total internal reflection at the interface between propagationcomponent 330 and buffer component 320 such that the radiation ispropagated within propagation component 330 in direction 342. Thecollected radiation at first end 332 of propagation component 330 isgenerally incident on the interface between buffer component 320 andpropagation component 330 at an angle such that the radiation isrefracted or transmitted through buffer component 320 and may besubsequently coupled to an output component 340. In one example, anoutput component 340 is positioned proximate to first end 332 ofpropagation component 330 through an opening (not shown) in buffercomponent 320.

In one example the radiation source is a phosphorescence or fluorescencematerial applied to a lower surface (not shown) of buffer component 320or on top of a radiation directing component configured to redirect theresultant radiation. As such, the radiation produced from thephosphorescence or fluorescence material is transmitted through thelower portion 324 of buffer component 320 and is either transmitted intopropagation component 330 at an angle such that it is retained withinpropagation component 330 due to total internal reflection or istransmitted through propagation component 330, the upper portion 322 ofbuffer component 320 and is incident on radiation directing component310. Radiation directing component 310 is configured to reflect theincident radiation back into upper portion 322 of buffer component 320at an angle such that the radiation is transmitted into propagationcomponent 330 and retained within propagation component 330 due to totalinternal reflection.

In another example, wherein propagation component 330 is sealed withinbuffer component 320. Propagation component 330 includes aphosphorescence or fluorescence material and radiation directingcomponent 310 is configured to pass incident radiation from at leastdirection 339 such that at least a portion of the incident radiation istransmitted into propagation component 330. The incident radiationexcites or otherwise causes the phosphorescence or fluorescence materialto emit radiation. The emitted radiation is either propagated withinpropagation component 330 generally in direction 342 due to totalinternal reflection or is transmitted out of propagation component 330,through buffer component 320 and is incident on radiation directingcomponent 310. The emitted radiation is redirected or reflected byradiation directing component 310 back through buffer component 320 andinto propagation component 330 such that the emitted radiation ispropagated within propagation component 330 generally in direction 342due to total internal reflection. In one variation, radiation directingcomponent 310 is positioned on multiple exterior surfaces of buffercomponent 320.

Solar collectors 100, 200, and 300 are manufactured in one embodimentfrom extrudable material such as various plastics. Exemplary extrudedplastics include extruded acrylics and extruded polycarbonates availablefrom Bay Plastics Ltd located at Unit H1, High Flatworth, Tyne TunnelTrading Estate, North Shields, Tyne & Wear, in the United Kingdom. Inthe case of solar collectors 100, 200, 300 the propagation components130, 230, and 330 and the buffer components 120, 220, 260, and 320 areextruded separately and then assembled. In one example, the variouslayers are coupled together with a suitable optical adhesive. In anotherexample, the various layers are coupled together by pressing the layersinto contact with each other while the layers are at an elevatedtemperature to “thermally weld” the various layers together. In analternative method, propagation component 330 of solar collector 300 isfirst extruded and then buffer component 320 is extruded overpropagation component 330.

Light directing component 110, 210, and 310 in one embodiment is thencoupled to the respective assembled buffer components 120, 220, and 320with a suitable optical adhesive. In another embodiment, light directingcomponent 110, 210, and 310 is formed on a top surface of buffercomponent 120, 220, and 320. One example of light directing component110, 210, and 310 being formed on buffer component 120, 220, and 320 isthe stamping or pressing of a diffraction grating or ruling pattern inthe top surface of buffer component 120, 220, and 320.

In other embodiments of solar collectors 100, 200, and 300, the solarcollectors are assembled from cast components, such as cast acrylic, ora combination of cast components and extruded components or from opticalcomponents manufactured by various other manufacturing processes.Exemplary cast acrylic components include HESA-GLAS from Notz PlasticsAG and available from G-S Plastic Optics located 23 Emmett Street inRochester, N.Y. 14605.

Once the solar radiation reaches the first end of solar collector 100,solar collector 200 or solar collector 300, the solar radiation exitsthe respective propagation component 130, 230, 330 and is coupled to anoutput component 340 as diagrammatically shown in FIG. 6A. Outputcomponent 340 is configured to receive the solar radiation exitingpropagation component 330 and to transport and/or otherwise utilize thesolar radiation. Example output components include energy convertingcomponent 342, a second solar collector 344, and an optical transportcomponent 346.

Energy converting component 342 is configured to convert the solarradiation into another form of energy for storage or use. Example energyconverting components 342 include any photoelectrical transducer, or anyphotochemical transducer, or any type of radiation detector. An examplephotoelectrical transducer is a photovoltaic cell or solar cell. Anexample photochemical transducer is a synthetic chlorophyll which canabsorb the supplied radiation to produce fuels such as oxygen orhydrogen. Example radiation detectors include silicon detectorsavailable from Edmund Industrial Optics located at 101 East GloucesterPike, in Barrington, N.J./USA 08007.

Second solar collector 344 includes a light directing componentgenerally similar to light directing components 110, 210, 310, a buffercomponent generally similar to buffer components 120, 220, 260, 320, anda propagation component generally similar to propagation components 130,230, 330. Second solar collector 344 is configured to receive solarradiation exiting propagation component 330 of solar collector 300 fromat least a first direction, such as direction 341 in FIG. 7A and toredirect the solar radiation along at least a second direction, such asdirection 343 in FIG. 7A. In one example, the light directing componentof solar collector 344 is configured to receive solar radiation frommultiple directions corresponding to the multiple directions of totallyinternally reflected light rays within propagation component 330.Alternatively, second solar collector 344 is abutted to first end 302 ofsolar collector 300 and is configured to receive solar radiation exitingthe propagation component of solar collector 300 from at least a firstdirection directly into the propagation component of solar collector 344such that the solar radiation propagates within solar collector 344along with additional solar radiation being redirected and propagated bysolar collector 344.

Optical transport component 346 is configured to transport the solarradiation exiting propagation component 330 to a remote location.Optical transport component 346 operates similar to fiber optics andincludes a buffer component, such as buffer component 320, and apropagation component, such as propagation component 330 of solarcollector 300.

Referring to FIG. 6B, solar collector 300 in another embodiment iscoupled to a frame 348 and is coupled to an output component 340. Frame348 is coupled to a tracking component 350 which is configured to moveand position solar collector 300. Referring to FIG. 6C, solar collector300 is coupled to output component 340 and both solar collector 300 andoutput component 340 arc coupled to frame 348. Frame 348 is coupled to atracking component 350 which is configured to move and position solarcollector 300. Tracking component 350 is configured to move solarcollector 300 such that solar collector 300 is capable of tracking thesun throughout a given day and various seasons of the year. Trackingcomponent 350 comprises a positioning component 352, such as a motor,and a controller 354, such as a computer. Controller 354 is configuredto control positioning component 352 and hence the movement of solarcollector 300. In one example controller 354 executes instructions fromeither software or hardware which provide the preferred position ofsolar collector 300 for a given time of day and a given time of theyear.

Referring to FIGS. 7A-7C, a first example configuration of solarcollector 300 is shown wherein solar collector 300 is coupled to solarcollector 344 which in turn is coupled to optical transport component346. Incident solar radiation 360 is redirected by light directingcomponent 310 such that the solar radiation is propagated in propagationcomponent 330 generally in a direction 341. The solar radiation exitspropagation component 330 from portion 332 of propagation component 330and is incident on light directing component 370 of solar collector 344.Light directing component 370 is configured to redirect the solarradiation from propagation component 330 through buffer component 380and into propagation component 384 such that the solar radiation ispropagated within propagation component 384 generally along direction343.

The solar radiation exits propagation component 384 at portion 386 ofpropagation component 384 and is coupled into optical transportcomponent 346 through an adapter 381. Adapter 381 includes a propagationcomponent 387 and a buffer component 389. In one example, propagationcomponent 387 and propagation component 384 have approximately the sameindex of refraction and buffer component 389 and buffer component 380have approximately the same index of refraction. Adapter 381 isconfigured to propagate the solar radiation from a first end 383 to asecond end 385 by retaining the solar radiation within propagationcomponent 392 due to total internal reflection. Further, in theillustrated embodiment adapter 381 is configured to mate with agenerally quadrilateral cross-section of solar collector 344 at firstend 383 of adapter 381 and to mate with a generally circularcross-section of a first end 391 of optical transport component 346 atsecond end 385 of adapter 381. It should be understood that adapter 381is configured to couple together two components having dissimilar crosssections. Further, adapter 381 may be used in conjunction with couplers616 and 624 shown in FIGS. 12A and 12B and described below.

Optical transport component 346 includes a propagation component 392 anda buffer component 394. In one example, propagation component 392 andpropagation component 387 have the same index of refraction and buffercomponent 394 and buffer component 389 have the same index ofrefraction. Optical transport component 346 is configured to propagatethe solar radiation to a remote location by retaining the solarradiation within propagation component 392 due to total internalreflection.

Referring to FIG. 7D, solar collector 344 is replaced by solar collector344′ which operates generally identical to solar collector 344. Solarcollector 344′ differs from solar collector 344 in that propagationcomponent 384′, buffer component 380′, and light directing component370′ are generally cylindrical in shape. As shown in FIG. 7D first end332 of solar collector 300 has been modified to have a concave extentconfigured to mate with light directing component 370′ of solarcollector 344′. In one embodiment, solar collector 344′ is made from anoptical transport component 346 having a generally circularcross-section along its extent and a light directing component 370′coupled to a portion of buffer component 394 of optical transportcomponent 346.

Referring to FIG. 7E, solar collector 344′ is formed from a circularoptical transport component 346 having two light directing components370 a and 370 b. Light directing component 370 a is configured toreceive solar radiation from solar collector 300 a propagating indirection 347 and light directing component 370 b is configured toreceive solar radiation from solar collector 300 b propagating indirection 341.

In some applications, the solar collectors of the present invention areused on surfaces of buildings, such as roofs, or exterior walls tocollect solar radiation and to provide the solar radiation to an outputcomponent or for lighting applications. Referring to FIG. 8, a side,elevational, schematic representation of a plurality of solar collectors400 affixed to a roof 422 of a building 421 is shown. Solar collectors400 are generally similar to solar collectors 100, 200, and 300. Asstated previously the radiation collected by solar collector 400 iscoupled into an output component 340. As illustrated in FIG. 8, solarcollectors 400 are coupled through additional solar collectors (notshown) to optical transport components 445 a, 445 b. Optical transportcomponents 445 a, 445 b in turn transport the solar energy collected bysolar collectors 400 to a remote location, such as an interior 423 ofbuilding 421 as shown in FIG. 8. As such, optical transport components445 a, 445 b provide the solar radiation for remote lightingapplications or for coupling to an output component 340, such as anenergy converting component 342. It is therefore possible with thepresent invention to collect solar radiation at a relatively hightemperature environment and to transport that radiation to a relativelylower temperature environment. As such, energy converting component 342can be supplied with adequate amounts of solar radiation and also bepositioned in an environment that correlates to a preferred operatingcondition of energy converting component 342.

Referring to FIG. 9A, a first embodiment of solar collector 400 isshown. Solar collector 400 is configured as an alternative toconventional shingles, for use on roof 422. Solar collector 400 operatesgenerally identical to solar collectors 100, 200, 300 and includes alight directing component 410, a buffer component 420, and a propagationcomponent 430. Further, solar collector 400 includes an attachmentcomponent 440 configured to receive fastening components (not shown),such as nails, screws or staples, to secure solar collector to roof 422of building 421. Attachment component 440 is made of a material suitablefor accepting fastening components and securing solar collector 400 toroof 422 of building 421.

Since solar collector 400 is secured to roof 422, light directingcomponent 410 is configured to receive solar radiation from multipledirections and to redirect the incident radiation such that it ispropagated within propagation component 430. Further, light directingcomponent 410 is configured to receive solar radiation corresponding tomultiple wavelengths. Solar collector 400 further includes a protectivecomponent (not shown) which overlays at least light directing component410 to protect light directing component 410 from the elements and otherpotential sources of damage. The protective component is comprised of amaterial that has good optical transmission properties and is generallyweather-resistant. In an alternative embodiment, light directingcomponent 410 is positioned below buffer component 420 to protect lightdirecting component 410 from the elements.

When a plurality of solar collectors 400 are positioned on roof 422, asshown in FIG. 8, a bottom portion 442 of buffer component 420 of a firstsolar collector overlaps a top portion 444 of attachment component 440of an adjacent and lower solar collector, similar to how conventionalshingles overlap when positioned on roof 422. In one variation of solarcollector 400, either top portion 444 of attachment component 440 orbottom portion 442 of buffer component 420 has an adhesive appliedthereto to assist in securing adjacent overlapping solar collectors 400to each other.

In another embodiment of solar collector 400, attachment component 440is replaced with an attachment component 460. Attachment component 460includes a first portion 462 to receive light directing component 410,buffer component 420 and propagation component 430 of solar collector400, the optical component, and a second portion 464 to receivefastening components (not shown) to secure solar collector 400 to roof422. Portion 462 of attachment component 460 is recessed relative toportion 464 such that light directing component 410 is generally flushwith portion 464 of attachment component 460. Lower portion 442 ofbuffer component 420 is secured to a top surface 466 of attachmentcomponent 460 with an adhesive.

In one variation of solar collector 400, attachment component 440 orattachment component 460 are colored to given the appearance oftraditional shingles or other roofing or building materials such thatthe roof appears aesthetically the same as a traditional roof. Further,a top surface 468 of solar collector 400 includes indicia (not shown) togive the appearance of the tabs of traditional shingles.

In another variation of solar collector 400, solar collector 400 is madefrom one or more flexible materials. As such, solar collector 400 iscapable of being distributed as a roll of material that is applied toroof 422 by unrolling the roll on roof 422 to extend along an extent ofroof 422, as a first row of “solar sheeting”. The first row of “solarsheeting” is attached to roof 422 with fastening components. Solarcollector 400 is then cut to length such that at least one of the endsof solar collector 400 includes a first surface 432 of propagationcomponent 430. An output component 340 (as shown in FIG. 6A), such asenergy converting component 342, another solar collector (not shown), oroptical transport components 445 a and 445 b, is then coupled to the endof solar collector 400 including first surface 432. Next, a second rowof “solar sheeting” are positioned by unrolling the remaining roll ofsolar collector 400 such that a portion of the second row overlays thefirst row and repeating the steps of fastening, trimming and couplingthe second row. This operation is repeated for subsequent rows of “solarsheeting”.

In some instances, a row of “solar sheeting” is comprised of twoseparate sections of solar collectors, such as pieces from two rolls ofsolar collectors. The two sections of solar collectors may be coupledtogether by trimming the adjacent ends of each solar collector andeither coupling the two sections together with an optical adhesive orcoupling each end of the adjacent ends to an intermediate opticalcoupler, such as an optical transport component. As shown in FIG. 14,two sections of solar collector 400, sections 400 a and 400 b, arecorrected together with an optical transport component 480. Sections 400a and 400 b, each include a respective propagation component 430 a and430 b and a respective buffer component 420 a and 420 b. Opticaltransport component 480 includes a buffer component 482 and apropagation component 484 which is configured to receive light ray 490from propagation component 430 a into propagation component 484 and tosupply the solar radiation to propagation component 430 b in solarcollector 400 b. In one example an optical adhesive is positionedbetween solar collector 400 a and optical transport component 480 andbetween solar collector 400 b and optical transport 480 to couple solarcollector 400 a and 400 b to optical transport 480. In another example,optical transport 480 includes detents (not shown) on surfaces 492 and494 of first elongated end 486 and on surfaces 496 and 498 of secondelongated and 488. The detents are sized and configured to couple solarcollectors 400 a and 400 b to optical transport 480.

Referring to FIGS. 10 and 11, a solar collector 500 is shown. Solarcollector 500 includes a plurality of light directing components 510, afirst buffer component 520, a propagation component 530, and a secondbuffer component 540. Light directing components 510 are positionedwithin first buffer component 520 and oriented at an angle to topsurface 522 of first buffer component 520. A lower portion 512 of lightdirecting components 510 is spaced apart from a lower portion 525 offirst buffer component 520 such that light directing components 510 donot touch propagation component 530. In an alternate embodiment solarcollector 500 is similar to solar collector 100 and does not include asecond buffer component 560.

Solar collector 500 operates in a similar manner to solar collectors100, 200, 300, and 400 of the present invention. Solar radiation, asrepresented by light ray 550, enters first buffer component 520 from atleast a first direction 539 through top surface 522 and is redirected bylight directing component 510 along at least a second direction 543 aslight ray 552 a. Light ray 552 a is incident on interface 524 betweenfirst buffer component 520 and propagation component 530 at an angleΘ_(552a) and is refracted into propagation component 530 at an angleΘ_(554a1). Light ray 554 a propagates through propagation component 530and strikes second buffer component 560 at an angle Θ_(554a2) atinterface 526. The refractive indexes of first buffer component 520,propagation component 530, and second buffer component 560 as well asthe angle of light ray 552 a directed by light directing component 510are chosen such that angle Θ_(554a2) and subsequent angles (Θ_(556a2),Θ_(558a2) . . . ) satisfy the requirements generally expressed inequations 3 and 4, thereby retaining light rays 554 a, 556 a, 558 a andsubsequent rays within propagation component 530 by total internalreflection and propagated generally in direction 541 toward first end532. Alternatively interface 526 includes a reflection coating toreflect light rays 554 a and 554 into propagation component 530. In yetfurther alternative embodiments, surfaces 521, 531, 561 of first buffercomponent 520, propagation component 530, and second buffer component560, respectively, include a reflection coating.

In the illustrated embodiment, light directing components 510 are showngenerally planar. In alternative embodiments the light directingcomponents are concave ill shape. The concave shape of the lightdirecting components provides an additional mechanism by which incidentsolar radiation from multiple directions can be coupled into thepropagation component by the light directing components.

Referring to FIGS. 12 a and 12 b multiple optical transport components346, such as optical transport components 346 a and 346 b may be coupledtogether to form an optical connector 600. Optical transport components346 a and 346 b each include a respective propagation component 384 aand 384 b and buffer components 380 a and 380 b. Optical connector 600is shown as a T-connector, however, optical transport components 346 aand 346 b may be coupled at a variety of angles. Optical connector 600is configured to couple radiation propagating within propagationcomponent 384 b of optical transport component 384 b generally indirection 602 into propagation component 384 a of optical transportcomponent 346 a such that the coupled radiation is retained withinpropagation component 384 a and is propagated generally in direction 604or in direction 606 or in both direction 604 and direction 606 dependingon the characteristics of light directing component 610.

Referring to FIG. 12 b, light directing component 610 is coupled to,formed on, or otherwise positioned on surface 612 of optical transportcomponent 346 a. Light directing component 610 is further coupled to, orformed on, or positioned adjacent to a first end 614 of opticaltransport component 346 b. First end 614 is shown as being configured tomatch the contour of surface 612 of optical transport component 346 a.However, first end 614 maybe flat, concave, convex, or additionalconfigurations. In one example, light directing component 610 includes aholographic element and is coupled to surface 612 of optical transportcomponent 346 a and first end 614 of optical transport component 346 bwith an optical adhesive. In another example, optical transportcomponent 346 a, optical transport component 346 b and light directingcomponent 610 are formed as an integral optical connector.

In a further example of optical connector 600, optical transportcomponent 346 a and optical transport component 346 b are furthersecured to light directing component 610 with a coupler 616. Coupler 616includes a first portion 618 and a second portion 620 which areconfigured to wrap around surface 612 of optical transport component 346a and to be adhered to a surface 622 of optical transport component 346b.

As shown in FIG. 12 b, an additional coupler 624 is shown. Coupler 624includes a cylindrical body 626 having an interior surface 628 sized toreceive surface 612 of optical transport component 346 a and a similarsurface of an additional optical transport component (not shown).Optical transport component 346 a may be secured to coupler 624 and theadjacent optical transport component (not shown) with a suitable opticaladhesive.

In yet another example of optical connector 600, optical transportcomponent 346 a and optical transport component 346 b are secured to afixture or frame (not shown) and are positioned such that first end 614of optical transport component 346 b is positioned proximate to surface612 of optical transport component 346 a. Further, light directingcomponent 610 is either positioned in the space between opticaltransport component 346 a and optical transport component 346 b, formedon first end 614 of optical transport component 346 b, formed on surface612 of optical transport component 346 a, coupled to first end 614 ofoptical transport component 346 b, or coupled to surface 612 of opticaltransport component 346 a.

It is possible, therefore with optical connectors 600, to have aplurality of optical transport components 346, such as optical transportcomponent 346 b, each having a first end 614 positioned generallyradially to a main optical transport component 346, such as opticaltransport component 346 a. Each of the radially placed optical transportcomponents 346 b are optically coupled to main optical transportcomponent 346 a through a light directing component, such as lightdirecting component 610.

As such with optical connectors 600 it is possible to create a networkof optical transport components 346. Referring to FIG. 13, an opticalnetwork 700 is shown. Optical network 700 includes plurality of solarcollectors 702 a-d, each configured to collect incident radiation and tocouple the collected radiation into an optical transport component, suchas optical transport components 704 a-d. Each optical transportcomponent 704 a-d is configured to transport the collected radiation. Asshown in FIG. 13, optical transport component 704 a and 704 b transportthe radiation collected by solar collectors 702 a and 702 b,respectively, generally in a direction 706 while optical transportcomponent 704 c and 704 d transport the radiation collected by solarcollectors 702 c and 702 d, respectively, generally in a direction 708.

Optical transport components 704 a-d, each is coupled to a main opticaltransport component 704 e at connections 710 a-d. Connections 710 a-dare configured to couple the radiation transported by optical transportcomponent 704 a-d into optical transport component 704 e such that theradiation is propagated within optical transport component 704 e ineither direction 712 or direction 714 or in both direction 712 anddirection 714. Each of connections 710 a-d includes a light directingcomponent (not shown) whose characteristics determines the direction oftravel of the radiation from the corresponding optical transportcomponent 704 a-d within optical transport component 704 e, eitherdirection 712, direction 714 or a combination of direction 712 and 714.In one example, connections 710 a-d include optical connectors 600similar to the optical connectors illustrated in FIGS. 12A and 12B suchthat optical transport component 704 e is comprised of several segmentsinterconnected with optical connectors 600. In another example,connections 710 a-d include optical connectors 600 as discussed abovewherein optical transport component 704 e is a main optical transportcomponent and optical transport components 704 a-d are radiallypositioned optical transport components.

Once the radiation transported by optical transport components 704 a-dis coupled into optical transport component 704 e, it is deliveredeither to another connection, such as connection 710 e or to an end 716of optical transport component 704 e. As illustrated in FIG. 13connection 710 e couples the radiation propagating in optical transportcomponent 704 e in direction 712 into an optical transport component 704f. The radiation coupled into optical transport component 704 f iseither propagated generally in direction 706, generally in direction708, or in generally in both directions 706 and 708 depending on thecharacteristics of the light directing component corresponding toconnection 710 e. The radiation coupled into optical transport component704 f is propagated to either a first end 718 or a second end 720 ofoptical transport component 704 f. The radiation propagated to end 716of optical transport component 704 e or first end 718 or second end 720of optical transport component 704 f is then supplied to an outputcomponent, such as output component 340 or for lighting applications.

Optical network 700 is shown in FIG. 13 for use in the collection ofsolar radiation. However, it should be understood that additional typesof optical networks are envisioned. For instance, optical connectors 600can be configured to couple multiple optical fibers together in anoptical network. As such, optical connectors 600 are capable of use tocouple optical signals, such as data signals, from a first fiber opticcable, such as optical transport component 346 b, into a second fiberoptic cable, such as optical transport component 346 a.

In one example, light directing component 610 is configured to redirectradiation propagating in optical transport component 346 b having afirst wavelength, such as 632.8 nanometers, generally along direction604 in optical transport component 346 a and radiation of a secondwavelength different than 632.8 nanometers generally along direction 606in optical transport component 346 a. As such, based on the wavelengthof radiation propagating within optical transport component 346 b lightdirecting component 610 acts as an optical switch to send radiation of afirst wavelength along first direction 604 of optical transportcomponent 346 a or a first optical circuit and radiation of a secondwavelength along second direction 606 of optical transport component 346a or a second optical circuit. Further, if radiation containing both thefirst and the second wavelengths is propagating within optical transportcomponent 346 b as first and second data signals, light directingcomponent 610 acts as an optical separator or filter by sendingradiation of a first wavelength, the first data signal, along firstdirection 604 of optical transport component 346 a and radiation of asecond wavelength, the second data signal, along second direction 606 ofoptical transport component 346 a. Although the above example discussesthe use of optical connector 600 as an optical switch or opticalseparator for two distinct wavelengths, it is contemplated that opticalconnector 600 can be used as an optical connector, an optical switch, oran optical separator for one, two, three or more distinct wavelengths.

In another example, optical transport component 346 b is replaced withan optical source, such as a laser, a laser diode, a light-emittingdiode, photochemical radiation sources such as a phosphorescence orfluorescence material, or other radiation producing component. As such,the radiation produced by the optical source is coupled into opticaltransport component 346 a through light directing component 610.

Referring now to FIGS. 15 a and 15 b, exemplary photocollectors 800 and802 (e.g., solar radiation collectors) are shown. It is initially notedthat the only difference between photocollectors 800 and 802 is theconfiguration of the light directing components within the first layerof the assembly, which is a buffer component region 820. Whilephotocollector 800 includes a plurality of louvers 810 as its lightdirecting component mechanism, photocollector 802 includes a diffractiongrating 812 as its light directing component, such as shown anddescribed with respect to light directing component 310 of FIG. 1 above.Operationally, the diffraction grating 812 is configured to cause a lossof energy to be imparted on the light rays as they are deflected withinthe collector (i.e., approximately a 30% drop in power is possiblewithin the grating apparatus), while no such energy loss is causedwithin the louver mechanism 810. In addition to the buffer region 820,both photocollectors 800 and 802 also include a propagation componentlayer 830 and a collector region 840.

The propagation component layer 830 includes a plurality of windows 836that are configured to allow the propagated light rays 801 to enter thecollector region 840. In turn, the collector region 840 includes aplurality of regions 845 having transparent refractive index materialwhere the refractive index increases in a smooth fashion and thendecreases to a magnitude equal in refractive index to the beginning ofthe region 845. The photocollectors also include a light directingcomponent 870 (FIG. 15 c) and a photocollector 844 including a buffercomponent 880 and a propagation component 882. Finally, thephotocollectors 800 and 802 also include an optical transport 846 thatis configured to transport the solar radiation exiting the collectors toa remote location. As shown in FIG. 15 c, optical transport 846 operatessimilar to fiber optics and includes a buffer component 894 and apropagation component 892, such as discussed in detail above withreference to optical transport 346. In other words, incident radiation(e.g., solar radiation) is redirected by the light directing component(e.g., louvers 810 or diffraction grating 812) such that the radiationis propagated in the propagation component layer 830 generally in adirection 841. The radiation exits propagation component layer 830through one of the plurality of windows 836 and enters the collectorregion 840. Once the radiation reaches portion 832 of the collectorregion 840, it is incident on light directing component 870 ofphotocollector 844. The light directing component 870 is configured toredirect the radiation from the collector region 840 through the buffercomponent 880 and the propagation component 882 of the photocollector844 such that the radiation is propagated within the propagationcomponent 882 of photocollector 844 generally along direction 843.

The radiation exits the propagation component 882 and is provided intothe optical transport component 846, which is configured to propagatethe radiation to a remote location by retaining the radiation withinpropagation component 892 due to total internal reflection (“TIR”). Toaccomplish this, the circumference of the propagation component 892 ischosen so that it is large enough to completely circumscribe the squareinner propagation component 882 of photocollector 844, and particularlysuch that the collected light energy is completely transferred to thepropagation component region 892 with no loss of energy through suitablerefractive matching and optical coupling.

A detailed explanation of how solar collector 800 operates is nowprovided with reference to FIG. 16. According to this exemplaryembodiment, vertical light rays 801 (solar photons) enter buffercomponent layer 820 from above the collector 800 and are deflected fromthe vertical by the set of light directing components or louvers 810.The light directing components 810 deflect the rays towards thepropagation component layer 830 at an angle. The louvers are constructedof material with a refractive index less than the other materialsurrounding it in the buffer component layer 820. Examples of variousmaterials from which the louvers may be constructed (as well as theother materials and components of the present photocollectors) are shownin Table 1 above. For example, if the refractive index of the louvermaterial has an index of refraction of 1.0 (e.g., air) and thesurrounding material has an index of refraction of 1.5, the criticalangle of incidence between the two materials at the contact interface835 is 41.8 degrees. If the light rays strike a louver surface tilted at50 degrees from horizontal, the angle of incidence of the vertical lightray at the louver interface is 50 degrees and greater than the criticalangle of 41.8 degrees. This ray is totally reflected at the louversurface with 100% conservation of energy. The angle of incidence at theinterface 835 is 85 degrees. In a similar fashion, a 45-degree louvertilt provides a TIR reflected ray horizontal to the collector surface,and a 60-degree louver tilt provides a 60-degree angle of incidence atinterface 835. An adequate operating angle of incidence at the interface835 is expected to lie between 60 and 80 degrees.

The louvers are designed to interact with the totality of the verticallight rays 801 reaching the surface of buffer region 820. As such, asthe tilt of the louvers change, the space between them needs to beadjusted to interact with all rays 801. The rays 801 hitting the upperhalf of straight louvers 810 will by geometric principles hit thebackside of adjacent louvers. A remedy for this circumstance is toimpart a slight concavity 803 to the upper half of the louvers so thatthe light hitting the upper half of a particular louver 810 will reachinterface 835 and not interact with either an adjacent louver or thelouver that a ray hit initially. The operation of such concavity isshown in further detail in FIG. 17. The incident angle at the surface ofinterface 835 will decrease depending upon this upper louver concavitybut will not result in a substantial diminution of operation, since therange of incidence angle has an operating range of 15 degrees or more.

When the rays hit the interface 835 of the propagation component layer830, some diffraction and reflection will occur since the refractiveindex of layer 830 is greater than the refractive index of layer 820(see for instance the light rays labeled as reference numeral 801 a). Incertain exemplary embodiments, approximately 20% reflection will be lostdue to the reflected light. It should be understood and appreciatedherein, however, that this loss can be optimized by changing the angleof incidence of the light ray. For example, assuming an interfaceconsisting of a material with a refractive index of 1.0 (air) and asubsequent material to which the light is directed to has a refractiveindex of 2.0 (the critical angle of incidence for this system interfaceis 30 degrees), the average reflection coefficient of light for an angleof incidence of 0 degrees (perpendicular to the plane of incidence) isapproximately 11%. That is, 89% is transmitted and 11% is reflected backto the light source. As the angle of incidence is increased at 835, theamount of reflected light increases according to the Fresnel equationsof light behavior such that approximately 20% of light is reflected upto approximately a 70 degree angle of incidence at interface 835. Incertain exemplary embodiments, the index of refraction for the buffercomponent layer is from about 1.0 to about 1.3 and the index ofrefraction for the propagation component layer 830 is from about 1.5 toabout 2.0. It is further anticipated that a gradual transition from onerefractive index to another can be achieved at interface 835, as opposedto a discrete interfacial barrier, such that no energy loss will occuras light travels from region 820 to region 830.

Once rays 801 enter the propagation component layer 830, no loss isexpected to occur due to the operation of the rays within the secondlayer. Rays 801 will continue to exhibit total internal reflection offinterface 835 and propagation component structures 837 until they enterone of the plurality of windows 836 whereupon the rays will enter thecollector region 840. The positive slope of the upper surface ofreflecting element 837 will impart an increase in the incident angle ofray 801 as it travels towards interface 835 and after it has reflectedoff the component 837. This positive slope will result in the angle ofincidence of ray 801 to be greater than the critical angle necessary toprovide total internal reflection at the 835 interface. Generally, therefractive index difference between component 837 and the surroundingmaterial comprising layer 830 is such that total internal reflectionwill occur on all surfaces of the component 837 at the incidence anglesexperienced by ray 801 as it interacts with component 837. The spacesbetween components 837 (so-called “windows” 836) can be adjusted suchthat overlapping configurations can occur. While the generalconfiguration of the device would remain the same, it has been foundthat increasing the spacing between the windows may be beneficial interms of the angles in the system and the refractive index materialsemployed within the system.

Rays 801 will continue generally to the right as indicated by arrow 847,entering the variable refractive regions 845 of transparent refractiveindex material. Regions 845 are characterized by smooth increases inrefractive index starting at or after the leftmost point of component837 until a peak is reached upon which the refractive index returns tothe refractive index existing at the front of region 845, where thelight 801 initially enters 845. This region is where entering light hasa possibility of entering the window area from below and exiting thephotocollector. To prohibit this circumstance, the incoming ray is bentgenerally towards the center of collector region 840 such that it missesentering the window region from below since the material through whichit is traveling is increasing in refractive index. More particularly, ifeach medium has a different refractive index, as light passes from onetransparent medium to another, it can change speed and bend. How muchthis happens depends on the refractive index of the mediums and theangle between the light ray and the line perpendicular (normal) to thesurface separating the two mediums (medium/medium interface). The anglebetween the light ray and the normal as it leaves a medium is called theangle of incidence. The angle between the light ray and the normal as itenters a medium is called the angle of refraction. Refractive indexescan be found experimentally by providing two media optically coupled toeach other, directing light into the first medium, through theinterface, and into the second medium and then measuring the bending oflight at the interface, thereby defining the angle of incidence andangle of refraction. Using Snell's Law (eq. 1) the refractive index ofone medium can be related to another medium's refractive index andcalculated, once the angle of refraction and angle of incidence aredetermined.

Regions 845 use gradual changes in refractive index to effect lightbending. When traveling through regions 845, the light does notencounter a discrete interface separating abrupt changes in refractiveindex, rather it gradually alters speed, thereby not experiencingreflective loss at a defined interface and conserving ray energy. As itproceeds to exit region 845 (finishes passing by and below the windowarea) it bends away from the central region of 840 since it travelsthrough material that is decreasing in refractive index. Light rayssufficiently in front of the window area would reflect off thehorizontal surface of component 837 and then proceed generally downwardto the right along arrow 847 and miss the window area. For light headedtowards the window area and within 845, a gradual transition of arefractive index value of 1.5 to a refractive index of 2.0 would yieldan approximate 10-degree shift towards the central region of collectorregion 840 by the end of the window (the beginning of the horizontalportion of component 837). Upon exiting region 845, the light ray wouldreturn to the same direction it was traveling prior to entering thecomponent region 845 and continue TIR (total internal reflection)through component 840. Light not heading towards a window area wouldexperience the transition of ray directional change when travelingthrough the component 837 with no loss of operation. The gradual changein refractive index permits a change in ray direction without loss ofpower with directional change as occurs at discrete interfacialboundaries with abrupt refractive index changes engendering reflectiveand refractive phenomena to occur. The horizontal size of the window836, is dependent upon the geometrical shape (e.g., triangular,hexagonal, pentagonal, etc.) and the spacing of the components 837 andmay be modified to suit refractive indexes and angular specificationsemployed, however the general features and operation of the deviceoperation will remain the same.

This process is then repeated until all of the light rays arrive at therightmost region of the collector and enter the optical transportcomponent 846. At the rightmost region of the collector, the sameprocess also directs the light rays to the corner of the plane of thesurface device as an effective collected amount of light energy in aconfined space of arbitrary size and area. It should be understood andappreciated herein that optimizing the distances between the propagationcomponent structures within the second layer in the horizontal direction(thereby altering the window region size and orientation) will determinewhere the modified refractive index region will exist in size andintensity.

Although the invention has been described in detail with reference tocertain illustrated embodiments, variations and modifications existwithin the scope and spirit of the present invention as described anddefined in the following claims.

1. A propagation apparatus for electromagnetic radiation, thepropagation apparatus comprising a first plurality of regions eachhaving a first index of refraction; and a second plurality of spacedapart regions interleaved with the first plurality of regions, an indexof refraction of each of the second plurality of spaced apart regionsgenerally increases from the first index of refraction at a leading edgeof the spaced apart region to a peak value and then decreases towardsthe first index of refraction at a trailing edge of the spaced apartregion, wherein the electromagnetic radiation traverses generally in afirst direction through a first region of the first plurality ofregions, followed by a first region of the second plurality of spacedapart regions, followed by a second region of the first plurality ofregions, and followed by a second region of the second plurality ofspaced apart regions.
 2. The propagation apparatus of claim 1, whereinthe peak value index of refraction of the first region of the secondplurality of spaced apart regions is about 133 percent of first index ofrefraction.
 3. The propagation apparatus of claim 2, wherein the firstindex of refraction is about 1.5 and the peak value is about 2.0.
 4. Thepropagation apparatus of claim 1, wherein the peak value index ofrefraction of the first region of the second plurality of spaced apartregions gradually transitions from the first index of refraction to thepeak value index of refraction.
 5. The propagation apparatus of claim 2,wherein the first index of refraction is about 1.5 and the peak value isabout 2.0.